1. (Science: astronomy) a constellation. A small cluster of stars.
2. An asterisk, or mark of reference. Three asterisks placed in this manner, <asterism/, to direct attention to a particular passage.
3. (Science: chemistry) An optical property of some crystals which exhibit a star-shaped by reflected light, as star sapphire, or by transmitted light, as some mica.
Origin: gr, fr. Star; cf. F. Asterisme.